Avances en virología de cetáceos: caracterización molecular de nuevas secuencias de morbilllivirus y Herpesvirus
PhD Thesis defense by Edwige Nina Belliere at the Faculty of Veterinary Medicine of the Complutense University of Madrid
October 1st, 2012
Cetaceans are probably the best sentinel organisms in the marine ecosystem. However, monitoring the health of these creatures under natural conditions is not easy, due to ethical and logistical obstacles. Therefore, the study of the animals stranded on coasts is an essential part of any health study. Within viral diseases, the two basic diseases that can cause the animals’ death are: infection by Cetacean morbillivirus (CeMV) and by herpesvirus (HV). CeMV is considered the most virulent infectious agent for cetaceans. To date there are three clusters of strains described, which are named: dolphin morbillivirus (DMV), porpoise morbillivirus (PMV) and pilot whale morbillivirus (PWMV). With regard to the HV, these can cause different symptoms which range from reproductive or cutaneous problems to encephalitis and viremia, and may cause anything from immunosuppression to systemic symptoms. However, to date, there are still very few references on their real impact on cetacean health. Starting with a tissue bank, and with the goal of understanding the role that CeMV plays in cetaceans’ health, the virus was diagnosed using PCR followed by the phylogenic analysis of the sequences obtained. These same tissues were subjected to molecular analysis to detect the presence of HV and evaluate the negative effect of these viruses on cetacean populations. Specifically, the following CeMV strains have been molecularly typed: a new strain of CeMV found in a Globicephala machrorhynchus stranded in 1996 in the Canary Islands and two DMV strains from the CeMV outbreak that occurred in the period from 2006-2008 on the Spanish and French Mediterranean coasts, which affected at least 60 Globicephala melas and 200 Stenella coeruleoalba. New HV sequences were also detected in this outbreak. Moreover, a new strain of HV was analysed in a Ziphius cavirostris stranded in the Canary Islands in 2005
